Oscillating screen structure



Dec. 12, 1961 HOPPE OSCILLATING SCREEN STRUCTURE 2 Sheets-Sheet 1 FiledJune 16. 1958 Dec. 12, 1961 e. HOPPE oscmmmc SCREEN STRUCTURE 2Sheets-Sheet 2 Filed June 16. 1958 a 57 1 2 41 b m w v W L. a w a b b Ma m: F

b v a W D m w r l a m f w v. s c

te tates ice 3,012,674 OCILLATING SCREEN STRUCTURE Gerhard ll-foppe,Frankiiampstrabe 69A, Gelsenkirchen, Germany Filed June 16, 1958, der.No. 742,128 4 (Ilaims. (Cl. 209-491) This invention has reference toscreens as used for separating particles of different size.

Oscillating screens or sieves serving the above purpose have often atendency to become clogged, particularly if the particles to beseparated are wet or damp.

It is, therefore, one object of this invention to provide screens forseparating particles of different size which have not the tendency toclog.

There are prior art screens wherein the danger of clogging has beensuccessfully avoided. These non-clogging screens are, however, subjectto various limitations and/ or drawbacks, and all of them are relativelycomplicated.

It is, therefore, another object of this invention to providenon-clogging or self-cleaning screens which, though highly effective,are simple, easy to manufacture and inexpensive.

Further objects and advantages of the invention will become apparent asthe following description proceeds, and the features of novelty whichcharacterize the invention will be pointed out with particularity in theclaims annexed to, and forming part of, this specification.

For a better understanding of the invention reference may be had to theaccompanying drawings in which-- FIG. 1 shows in form of an isometricview a screen embodying this invention in combination with aconventional oscillatory frame supporting the same;

FIG. la is a top-plan view of the screen structure of FIG. 1 shown on alarger scale;

FIG. 2 is a top-plan View of a modification of the screen structureshown in FIG. la;

FIG. 3 is a top-plan view of another screen structure having operatingcharacteristics similar to those of the structures of FEGS. 12; and

FIG. 4 is a section along A-A of FIG. 3.

Referring now to the drawings, and more particularly to FIG. 1 thereof,reference letters a have been applied to indicate an upper sieve frame.Upper frame a is supported on a base or base frame 0 by means of fourresilient rods or springs e of which but two can be seen in FIG. 1.Frame a supports the screen proper to which reference letter b has beenapplied. The screen proper has been shown but diagrammatically inFIG. 1. The woven screen structures fully shown in FIG. 1a and FIG. 2are intended to take the place of the screen proper indicated byreference letter b in FIG. 1. A pair of helical springs f interconnectsupper frame a and lower frame c. Lower frame c' is supported by aplurality of springs f" of which but two have been shown in FIG. 1. Ashaft g projects transversely across upper frame a and is adapted to berotated byan electric motor (not shown), supported by frame a. Shaft gsupports an eccentric weight d, is. a weight whose center of gravity isspaced from the longitudinal axis of shaft g. As a result. frame a andsieve b will be caused to oscillate, or vibrate, when shaft ,9 andweight d are rotated.

Referring now to FIG. la, the woven wire screen shown therein comprisesweft wires interwoven with warp wires. The terms weft wires and warp asapplied to the screen shown in FIG. la are intended to indicate that thewires extend at right angles and are interwoven in the fashion of yarnof which textile materials are made. The wires referred to as weft wiresmay extend either in a direction longitudinally of frame a and intransverse direction. The same applies as to the wires referred-to aswarp wires. In FIG. la wires a, b may be considered as weft wires andwires 0 as Warp wires. The woven sieve structure of FIG. la comprises afirst system of parallel wires 11 and a second system of parallel wiresb. Wires a and b are arranged in parallel and are interleaving, and thestretchability of wires a in a direction longitudinally thereof differsfrom the stretchability of wires b in a direction longitudinallythereof. The difference in stretchability between the wires a forming afirst system of wires and the wires b forming a second system of wiresis sufiiciently large to establish a tendency of relative movementbetween the constituent wires of said first system and the constituentwires of said second system when the screen oscillates under loadconditions as an integral part of the structure of FIG. 1, or in anequivalent arrangernent.

The difference in stretchability between the wires a and the wires b maybe achieved in a number of ways. Both wires a and b may be made of thesame material but their cross-section may differ as indicated in FIG.1a. As an alternative, the difference in stretchability may be achievedby selecting different materials for wires a and 1). Another means ofobtaining twosystems of parallel wires a, b and of establishing asubstantial difference in the stretchability thereof is to impart adifferent bias to the constituent wires of each system, in which casethe wires may be made of the same material and have equalcross-sections. As a further alternative for achieving substantiallydifferent degrees of stretchability one may resort to auxiliary springmeans for controlling the bias of either system of parallel wires a, bas will be more fully explained in connection with FIGS. 3 and 4.

I Referring now to FIG. 2, the wire screen shown therein comprises foursystems of wires. Reference character a has been applied to indicate asystem of horizontal wires, reference character b has been applied toindicate.

another system of horizontal wires, reference character a has beenapplied to indicate a system of vertical wires, and reference characterb has been applied to indicate another system of vertical wires.Horizontal wires a, b are arranged in interleaving relation and the sameapplies to vertical wires a, b. The stretchability of horizontal wires adiffers from the stretchability of horizontal wires b and thestretchability of vertical wires a differs. from the stretchability ofvertical wires b. The constituent wires of the two systems of horizontalwires a, b are interwoven with the constituent wires of the two systemsof vertical wires a, b in the fashion clearly shown in FIG. 2.

Referring now to FIGS. 3 and 4, the structure shown therein comprises afirst system of parallel wires a and a second system of parallel wiresb. Wires b are arranged parallel to and interleaving with wires a. Wiresa and b may be made of the same material and may have equalcross-sections. The frame structure for supporting wires a and bincludes two parallel bars c made of a relatively inflexible ornon-resilient material and four bars e made of a relatively flexible orresilient material. Bars e are arranged below bars 0, and separated fromeach other by spacer bars 01. A continuous wire a may be wound aroundbars 0 only, whereas a continuous wire b may be wound around bars e andbars 0, as clearly shown in FIG. 4. The spacer bars (1 are clampedagainst bars 0, thus preventing unwinding of wire a in case that thesame should break at any point thereof. The structure further comprisesclamping bars f having lateral grooves g for clamping the turns ofcontinuous wire b against spacer bars d, thus precluding unwinding ofthe turn of Wire b in case that the same should break at any pointthereof. The clamping action of bars d and f is achieved by a number ofscrews h arranged in spaced relation from each other i and projectingtransversely through bars f and d into bars 0.

It will be apparent from the foregoing that though Patented Dec. 12,196i wires a and b may have inherently the same stretchability in adirection longitudinally thereof, a different stretchability is impartedto wires (1 and b by virtue of the different nature of the terminalsupports and e thereof.

The structures shown in the drawings are primarily intended for gradingmoist coal of relatively small particle size, but may also be used for,and/or adapted for, other purposes.

It will be understood that, although I have shown and described indetail but preferred embodiments of my invention, the invention is notlimited thereto, and the illustrated embodiments may be modified andother embodiments made without departing from the spirit and scope or"the invention as set forth in the accompanying claims.

I claim as my invention:

1. In combination a woven screen for separating particles of difierentsizes and means for imparting an oscillatory motion to said screen, saidscreen comprising weft wires interwoven with warp wires, said weft wiresforming a first system and a second system of parallel screen wires, theconstituent wires of said second system being arranged parallel to andinterleaving with the constituent wires of said first system, theconstituent wires of said second system being adapted to have adifferent stretchability in a direction longitudinally thereof than theconstituent wires of said first system, and the difference instretchability between the constituent wires of said first system andthe constituent wires of said second system being sufficiently large toestablish a tendency of relative movement between the constituent wiresof said first system and the constituent wires of said second systemwhen said screen oscillates under load conditions.

2. In combination a woven screen for separating particles of diiferentsizes and means for imparting an oscillatory motion to said screen, saidscreen comprising weft wires interwoven with warp wires, said weft wiresforming a first system and a second system of parallel wires, theconstituent wires of said second system being arranged parallel to andinterleaving with the constituent wires of said first system, theconstituent wires of said second system being of a material differentfrom that of the constituent wires of said first system, and theproperties of the material of the constituent wires of said first systemand of the material of the constituent wires of said second system beingadapted to establish a tendency of relative movement between theconstituent wires of said first system and the constituent wires of saidsecond system when said screen oscillates under load conditions.

3. In combination a woven screen for separating particles of differentsizes and means for imparting an oscillatory motion to said screen, saidscreen comprising weft wires interwoven with warp wires, said weft Wiresforming a first system and a second system of parallel Wires, theconstituent wires of said second system being arranged parallel to andinterleaving with the constituent wires of said first system, and theconstituent wires of said second system having a sufficiently differentbias from the constituent wires of said first system to establish atendency of relative movement between the constituent wires of saidfirst system and the constituent wires of said second system when saidscreen osciilates under load conditions.

4. In combination a woven screen for separating particles of differentsizes and means for imparting an oscillatory motion to said screen, saidscreen comprising a first system of parallel wires and a second systemof parallel wires, the constituent wires or" said first system and theconstituent wires of said second system being arranged in parallelinterleaving relation and being adapted to have a differentstretchability in a direction longitudinally thereof, said screenfurther comprising a third system of parallel wires and a fourth systemof parallel wires, the constituent wires of said third system and theconstituent Wires of said fourth system being arranged in parallelinterleaving relation and being adapted to have a differentstretchability in a direction longitudinally thereof, and theconstituent wires of said first system and of said second system beingarranged at right angles to and interwoven with the constituent wires ofsaid third system and said fourth system.

References Cited in the file of this patent UNITED STATES PATENTS

